Coiling fin for tube launched missiles



:Sept 17, 13963 y 1H. PoiPENoE v conm@ 11m 'ma MUNCHED mssms Ema @am 131 1966 4 :Sheets-Shes?. .1

LAUNOHER TUBE CHARLES H. POPENOE INVENTOR.

4 from/ys Selt- T71 1953 cm1-rl.. PORENOE 3,193,886

` @grimms FIN FOR .MxssIfLzEs Fil-'ed om. 1:5, 19e@ CHARLES H. POPENOE INVENTOR.

Spfl 17,1963 `c. H. PoPENoE,

COILING FIN FOR TUBE LAUNCHED MISSILES 4 Sheets-Sheet 3 Filed Oct. 13, 1960 INVENTOR ATTORNEYS Sept. 17, 1963 c. H. PoPENoE coILING FIN FoR TUBE LAUNCHED MIssILEs Filed oct. 1s, 1960 4 Sheets-Sheet 4 INV ENTOR Y CHARLES H. POPENOE ATTORNEYS United States Patent O 3,163,856 CELING FIN FOR TUBE LAUNCHED MESSHJES Charles il. Popeline, Silver Spring, Md., assigner to the United States ef America as represented by the Secretary of the Navy l Filed Get. 13, 1969, Sei'. No. 62,5%.` 2 Claims. (Cl. lin-5d) This invention relates generally to missile fin structure; more particularly, it relates to a flexible iin forV use on missiles designed for launchers.

A common method of launching missiles, especially those of small caliber, is by employing a tubular launcher. Light weight tubular launchers may be employed for shoulder-launched missiles of the bazooka type, as well yas for aircraft and light ground vehicle launched Weapons. One of the principal problems associated with such tubelaunched missiles has `been -to provide n surfaces adequate -to aerodynamically stabilize the missile during flight, and yet provide a means to allow folding or retraction of -such surfaces into the missile, so that it may be fitted into a launching tube.

The primary object of this invention is to provide a low-cost, relatively simple iin for fulfilling the stabilization and aerodynamic control requirements of tubelaunched missiles, consisting of :flexible lin surfaces having lareas sufficient for purposes of assuring missile stability when erected, said surfaces being movable to positions lying about the missile in retracted positions.

Another object of the invention is to provide a flexible iin for tube-launched missiles, said fin being so constructed as to be self-erecting `after the missile has been launched.

It is also an object of lthe invention to provide a ilexible tin for tube-launched missiles that is so constructed as to become substantially rigid upon erection thereof.

A further object of the invention is to provide a locking device for a flexible iin, said device being so constructed as to cooperate with said fin to maintain the same in an erect position.

Other objects and many `of the attendant `advantages of this invention will be readily `appreciated as the same becomes better understood by reference -to the following detailed description when considered in connection with the accompanying drawings, wherein:

FIG. 1 is a `side elevation lof a missile, showing a plurality of fins in erected, in-llight, positions;

FIG. 2 is a view in elevation of a missile positioned in a launching tube, with its iins retracted and wrapped about the mid-portion and aft end of said missile;

FIG. 3 is an enlarged, perspective view of one of the fins;

FIG. 4 is a cross-section, on an enlarged scale, on line 4-4 of FIG. 2;

FIG. 5 is a detail sectional view, showing the root end of a iin Iin its retracted, wrapped position;

FIG. 6 is a fragmentary sectional view, similar to FIG. 5, but showing the fin portion in its erected position;

FIG. 7 is a detail sectional view, showing .a portion of a modified form of iin in Wrapped position;

FIG. 8 is a detail sectional view, showing the modifled iin of FIG. 7 in erected position;

FIG. 9 is an enlarged, perspective View of the modined fin of FG. 7; and

FIG. l0 is an exploded perspective view of the modied iin construction of FIG. 7.

Missiles of the type here involved are normally small caliber rocket missiles of the bazooka type. Such a missile is shown -at Z in FIG. l, as it would 'appear when in flight. 'Ihre missile 2 has a plurality of forward fins launching 4from tubular Patented Sept. l?, 1563 ice 4 and aft tins 6 thereon, each of which is constructed and secured to the missile in the same manner.

The dexible iin of the present invention may be wrapped around the adjacent outside circumference of the body of a missile in retracted position, but will 'become quite rigid whenin an erect position. The construction of zone of the fins 4 of the invention is shown in FlG. 3, wherein said iin is seen to be 4fabricated of two pieces of thin gauge, resilient material, such as spring steel, one piece each for the top and bottom lsurfaces 8 and 10, respectively. These pieces or sheets are preformed linto arcuate cross-section, much like metallic Venetian blind slats, and are placed together with their concave surfaces facing each other, and are then secured to one another, las by a seam weld, lat the leading, trailing and tip edges l2, 14 and 16, respectively.

The fins are each attached at their root ends to the body of a missile, in a manner that allows the upper and lower surfaces or sheets of the iin to be ilexed toward each other. Referring again to FlG. 3, the n 4 is attached at its root end i8 -to a forward hinge plate 24B and an aft hinge plate 22, said hinge plates being attached to the body of said missile. A forward hinge pin 21 is attached to the fin near the leading edge of the root end 18 thereof, :and is slidably and rotatably received within `the hinge plate 2t?. Similarly, an aft hinge pin 23 is attached to the lin 4 at its trailing edge, and is slidably and rotatably received in the hinge plate 2?.. Midway between the hinge plat-es Ztl and 22 a wing locking device 24- is provided. The device consists of -a missile mounted control member 26 which has near its outer edge an elongated vertical slot 2S. The center of the slot 2S is enlarged at 3d to a diameter sutlicient to accommodate two pivot pins 32 and 34, which pins are suitably secured to the central portions of the root end edges of the fin surfaces 8 and id, respectively. While the pivot pins are shown secured to the interior of 4the iin surfaces, it is to be understood that instead they could be secured to the exterior thereof. The surfaces 8 and lil have vertically aligned, oblong notches 33 and 35, respectively, therein of a size suicient to freely accommodate the outer end portion of the control member 26.

When the root end 18 of the iin 4 is secured to the missile in the tin-erect condition, with the surfaces 3 and l0 separated at their inner ends, as 4shown in FIGS. 3 and 6, the resultant airfoil structure is quite rigid; however, if the surfaces 8 Iand lil are squeezed together, as shown in FIGS. 4 and 5, the lin becomes suiiiciently flexible to permit it to be wrapped around a missile section having a comparatively small radius.

The n wrapping operation is effected as follows. The inner end portions of the fin surfaces S aud iti are manually squeezed toward each other until the pivot pins 32 and 34 engage, at which point the tin may -be rotated 90 to a position at which its plane will be tangent to the missile, as is indicated iby broken lines in FIG. 4. The notches '293` and 35 must lbe of suiicient depth to allow such rotation. The enlargement Sill of slot 2S will now receive the pins 32 and 34 and maintain the inner end portions of the surfaces 8 and lill in a squeezed-together, closed condition, and Ithe iin may be -wrapped partially about the missile body. As is shown in FG. 4, the lins may be of such length that the outer end portions of one will overlie the inner end portion of the adjacent iin about the missile body.

The fins 4 and 6 are shofwn in FIG. 2 of the drawing to be held in the Wrapped condition lby bands 36 and 37, respectively. A device (not shown) is incorporated to release the bands lafter the missile has been launched, thus releasing the wrapped fins. Where the ns might be snee-,sse

subject to damage during handling and transit, the bands 36 and 37 can be made of suicient width to cover conipletely the wrapped fins. Further, in some applications the bands could be eliminated entirely, and the fins held in a wrapped -condition by the launcher tube only.

As best seen Ain FIGS. l and 2, shallow circumferential recesses 3S and 39 are provided in the missile body in the area of the tins l4 and 6 in order that said iins when wrapped, will lie with their buter surfaces flush with the missile body surfaces. The volume required to store the wrapped fins is quite small, and after the fins have been erected, the recesses will have an area ruling effect, when properly faired, to lower transonic drag.

Upon release of the bands 36 and 37 after missile launch, the fins first tend to straighten themselves. The momentumbuilt up in this operation moves the iin 4 until it is perpendicular to the missile surface, at which point the surfaces S and it? pull away from each other, such action being ycaused by their resilient nature. The pins 32 and 34 will then move to opposite ends of the slot 28, and the iin will be locked in place in an erect, substantially rigid position. Y Y Y A modified form of wraparound fin is shown in FIGS. 7, 8, 9 and lt). Referring to FIG. 9, a iin is indicated generally at 4t), the iin having a [top surface 42 and a bottom surface 44, these surfaces being similar to the surfaces v8 and 1u shown in FIG. 3. The surfaces 42 and 44 are secured to one another at their leading, trailing and tip edges 46, 4S and 5t), respectively.

The root end of the iin has a pair of retainers 54 and 56 thereon, the retainer 54 being attached `to the top surface 42 and the retainer 56 to the bottom surface 44. The retainers 54 and 56 consist of pieces of resilient wire secured in position, as by welding, and extend almost the full width of the iin. The surfaces 42 and 44 have pairs of laterally spaced, vertically aligned notches 58 and 60 therein, said notches be-ing similar to the notches 33 and 35 in the n construction of FIG. 3.

A portion of a missile is shown in cross-section at 62 in FIGS. 7 and 8, and in perspective in FIG. l0. The missile has a plurality of recesses therein, one for each iin` One such recess is shown at 64. T-he recess 64 is shaped to generally correspond to the cross-sectional configuration of the inner end of an erected fin, and has an oblong faired locking plug 66 `disposed therein. Spaced springs 68, each of which has its inner end seated in a socket '70 within the recess 64 and its outer end in a socket 72 in the plug 66, are employed to urge the locking plug outwardly from said recess. A mounting plate 74 is secured to 'the missile about the recess 64 by a plurality :of screws 76, and has an opening 78 therein of the same shape as the cross-sectional configuration of the inner end of an erected iin. The opening 78 is smaller than the mouth of recess 64, and hence the plate forms a rim 80 against which a peripheral retaining flange 82 on the plug 66 can abut.

The plate 74 is of substantial thickness and has a locking groove 84 extending around the periphery of the opening 73, said groove being of a size to receive the retainers 54 and l'56. rllhe plate 74 also has a pair of spaced guides 8S thereon, one guide being received in each of the notches 58 and 60. Each guide has a cam slot 90 therein to receive pivot pin portions 55- and 57 of the retainers 54, 56, which portions 55 and 57 confront the notches 58 and '60. Ther guides 88 may be made with an inner portion integral with the plate 74 and an outer portion made separately and secured, as by welding, to the plate, the retainers 54, S6 first being placed in position.

The plug 66 is so shaped that the portion just above the retaining flange 82 thereof fits snugly within the interior of the erected fin adjacent the retainers 54 and 56. The upper portion of the plug has a cam-like surface 92 thereon, and spaced notches 94 are provided to permit the plug to extend into the lin .past the `guides 88.

The operation of the fin itl is best shown in FlGS. 7 and 8. The surfaces 42 and 44 are first collapsed against one another. The collapsed tin is then wrapped around the missile, as is shown in -f'ull lines in FIG. 7. The locking plug 66 is held in a depressed position, against the force of the springs 68, by the retainers l54 and 56, the pivot pin portions 5S and 57 of the retainers being positioned in the outermost portions of the cam slot 9d. When the iin is released from its wrapped position it will tend to erect itself, the fin being indicated at an intermediate position by the broken lines in FIG. 7. As the fin becomes erect the retainers S4 and 56 spread apart and are guided by the cam slot 9i) into the peripheral locking groove 34. The locking plug 66 is made free to move as the flanges spread, and moves into the interior of the iin until the final position shown in FIG. 8 is reached. When the lin 40 is fully erect, and the locking plug 66 is in place, said fin is quite rigid and can withstand considerable aerodynamic loading.

While only one locking device is shown to be employed in the iin construction of FIG. 3, a plurality thereof may be provided if desired. Similarly, the number of guides employed in the iin construction of FIGS. 7 to l0 is optional. ln both lin constructions there must be enough locking devices or guides to insure strength suicient to withstand aerodynamic loads encountered in flight.

The specific dimensions of a wrap-around fm for any particular application may be determined by calculation, such factors as panel load requirements, iin material and heat-treat properties, and missile body diameter being taken into consideration.

Obviously, many modifications and variations of thc present invention are possible in the light of the above teachings., It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In an aerial missile, a missile body, a iin comprising a pair of resilient, flexible sheets each having a Igenerally arcuate cross-section, la leading edge, a trailing edge, a tip edge and a root end, sai-d sheets being arranged with their concave sides facing each other and with said leading edges, said trailing edges and said tip edges contacting 'and lbonded together, said root ends and the central portions of said sheets being free and normally bowed apart when said fin is in an erect position, thereby providing a rigid lhollow airfoil of symmetrical cross-section, said iin becoming flat and flexible -upon movement of said bowed sheets and root ends toward each other and into engagement, said sheets having at least one pair of aligned notches, one notch of said pair extending inwardly from and being positioned centrally of the root end of each sheet, a pivot pin attached to each sheet at said troot end and confronting said notch, means mounted on said missile body :and connected with said root ends for securing said fin to said body and for permitting said n to be wrapped about said body when said iin has been made flexible by movement of the central portions and the root ends of said sheets into engagement, said securing means including a forward hinge plate, an aft hinge plate, a forward hinge pin, and an aft hinge pin, said hinge plates each having a bore therein and being secured to said missile body in aligned, spaced apart relationship, said hinge pins being secured to said iin at the opposite extremities of said root ends, said forward hinge pin projecting beyond said leading edges and being slidably and rotatably received within said bore in said forward hinge plate, and said aft hinge pin projecting beyond said trailing edges and being slidably and rotatably received within said bore in said aft hinge plate, and means attached to said body and engageable with said pivot pins for securing said n is an erect position, said last mentioned means including a locking device, said device being attached to said missile body and having therein an elongated slot including an enlarged central portion, both said pivot pins being received within said slot and being positioned within said enlarged central portion when said sheets and said root ends are in engagement, and being positioned at opposite ends of said slot when said n is in an erect position with said sheets and said root ends bowed apart.

2. In an aerial missile, ya missile body, a iin comprising a pair of resilient, flexible sheets each having a generally arcuate cross-section, a leading edge, a trailing edge, a tip edge and 'a root end, said sheets being arranged with their concave sides facing each other and with said leading edges, said trailing edges and said tip edges contacting a-nd bonded together, said root ends and the central portions of said sheets being free and normally bowed apart when said iin is in an erect position, thereby providing a rigid hollow ainfoil of symmetrical crosssection, said iin becoming iiat and iiexible upon movement of said bowed sheets and root ends toward each other and into engagement, said sheets having at least one pair of aligned notches, one notch of said piair extending inwardly from and being positioned centrally of the root end of each sheet, a. pivot pin attached to each sheet at said root end and confronting said notch, means mounted on said missile body and connected with said root ends for securing said fin to Said body and for permitting said lin to be wrapped about said body when said fin has been made Flexible by movement of the central portions and the root ends of said sheets into engagement, said securing means including a guide, said guide being secured to said missile :body in a position confronting said notches and having a cam slot therein, both of said pivot pins being disposed within said slot, and means attached to said body and engageable with said pivot pins for securing said iin in an erect position, said last mentioned means including a retainer secured to the outside ofl each said sheet at said root end, said missile -body having a recess means therein positioned to confrontrsaid root ends, said recess means including a peripheral groove portion of a size to receive said retainers and said pivot pins when said n is in an erect position with said sheets and said root ends :bowed apart, -a locking plug receivable within said recess means and adapted to extend into the interior of said erect iin, and resilient means positioned to urge said plug into said n.

References Cited in the file of this patent UNITED STATES PATENTS 2,858,765 Startzell Nov. 4, 1958 2,923,241 House v Feb. 2, 1960 2,924,175 lasse Feb. 9*, 1960 2,977,880 Kershner Apr. 4, 196'1 l FOREIGN PATENTS 1,219,694 France Dec. 28, 1959 

1. IN AN AERIAL MISSILE, A MISSILE BODY, A FIN COMPRISING A PAIR OF RESILIENT, FLEXIBLE SHEETS EACH HAVING A GENERALLY ARCUATE CROSS-SECTION, A LEADING EDGE, A TRAILING EDGE, A TIP EDGE AND A ROOT END, SAID SHEETS BEING ARRANGED WITH THEIR CONCAVE SIDES FACING EACH OTHER AND WITH SAID LEADING EDGES, SAID TRAILING EDGES AND SAID TIP EDGES CONTACTING AND BONDED TOGETHER, SAID ROOT ENDS AND THE CENTRAL PORTIONS OF SAID SHEETS BEING FREE AND NORMALLY BOWED APART WHEN SAID FIN IS IN AN ERECT POSITION, THEREBY PROVIDING A RIGID HOLLOW AIRFOIL OF SYMMETRICAL CROSS-SECTION, SAID FIN BECOMING FLAT AND FLEXIBLE UPON MOVEMENT OF SAID BOWED SHEETS AND ROOT ENDS TOWARD EACH OTHER AND INTO ENGAGEMENT, SAID SHEETS HAVING AT LEAST ONE PAIR OF ALIGNED NOTCHES, ONE NOTCH OF SAID PAIR EXTENDING INWARDLY FROM AND BEING POSITIONED CENTRALLY OF THE ROOT END OF EACH SHEET, A PIVOT PIN ATTACHED TO EACH SHEET AT SAID ROOT END AND CONFRONTING SAID NOTCH, MEANS MOUNTED ON SAID MISSILE BODY AND CONNECTED WITH SAID ROOT ENDS FOR SECURING SAID FIN TO SAID BODY AND FOR PERMITTING SAID FIN TO BE WRAPPED ABOUT SAID BODY WHEN SAID FIN HAS BEEN MADE FLEXIBLE BY MOVEMENT OF THE CENTRAL PORTIONS AND THE ROOT ENDS OF SAID SHEETS INTO ENGAGEMENT, SAID SECURING MEANS INCLUDING A FORWARD HINGE PLATE, AN AFT HINGE PLATE, A FORWARD HINGE PIN, AND AN AFT HINGE PIN, SAID HINGE PLATES EACH HAVING A BORE THEREIN AND BEING SECURED TO SAID MISSILE BODY IN ALIGNED, SPACED APART RELATIONSHIP, SAID HINGE PINS BEING SECURED TO SAID FIN AT THE OPPOSITE EXTREMITIES OF SAID ROOT ENDS, SAID FORWARD HINGE PIN PROJECTING BEYOND SAID LEADING EDGES AND BEING SLIDABLY AND ROTATABLY RECEIVED WITHIN SAID BORE IN SAID FORWARD HINGE PLATE, AND SAID AFT HINGE PIN PROJECTING BEYOND SAID TRAILING EDGES AND BEING SLIDABLY AND ROTATABLY RECEIVED WITHIN SAID BORE IN SAID AFT HINGE PLATE, AND MEANS ATTACHED TO SAID BODY AND ENGAGEABLE WITH SAID PIVOT PINS FOR SECURING SAID FIN IS AN ERECT POSITION, SAID LAST MENTIONED MEANS INCLUDING A LOCKING DEVICE, SAID DEVICE BEING ATTACHED TO SAID MISSILE BODY HAVING THEREIN AN ELONGATED SLOT INCLUDING AN ENLARGED CENTRAL PORTION, BOTH SAID PIVOT PINS BEING RECEIVED WITHIN SAID SLOT AND BEING POSITIONED WITHIN SAID ENLARGED CENTRAL PORTION WHEN SAID SHEETS AND SAID ROOT ENDS ARE IN ENGAGEMENT, AND BEING POSITIONED AT OPPOSITE ENDS OF SAID SLOT WHEN SAID FIN IS IN AN ERECT POSITION WITH SAID SHEETS AND SAID ROOT ENDS BOWED APART. 